This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Individuals with PAD suffer from low oxygen delivery as a consequence of arterial narrowing or obstruction that impairs blood flow. Treatment interventions for PAD such as revascularization have been reported to improve ankle-brachial index (ABI), an index of arterial obstruction, and increase maximal calf blood flow. The significance of understanding changes in vascular function following treatment for PAD is that more effective strategies can be developed to improve the underlying cardiovascular dysfunction inherent in individuals with PAD. We hypothesize that revascularization treatment for PAD will increase calf muscle hemodynamics and oxygenation during exercise, and that these changes will be positively correlated with changes in vascular function as assessed by pulse-wave velocity (index of arterial stiffness) and peak reactive hyperemia. Fifteen men and women with PAD will be recruited for this study and visit Noll Laboratory before treatment, 3-7 days after treatment, and following 4 weeks of recovery from treatment. During each visit, participants will be given: a walking impairment questionnaire;asked to rest during pulse-wave velocity and ABI; perform a total of 8 min of isometric calf muscle exercise while hemodynamics and peak reactive hyperemia are measured using Doppler ultrasound;perform a 6 min walk test to assess functional capacity;and lastly, rest again for repeat pulse-wave velocity and ABI measurements.